The present invention relates generally to the field of antennas and, in particular, to a new and useful plasma array that can be used for transmitting, receiving, filtering, reflecting and/or refracting radiation, particularly EM radiation.
Traditionally, antennas have been defined as metallic devices for radiating or receiving radio waves. The paradigm for antenna design has traditionally been focused on antenna geometry, physical dimensions, material selection, electrical coupling configurations, multi-array design, and/or electromagnetic waveform characteristics such as transmission wavelength, transmission efficiency, transmission waveform reflection, etc. As such, technology has advanced to provide many unique antenna designs for applications ranging from general broadcast of RF signals to weapon systems of a highly complex nature.
Plasma antennas have far more flexibility and potential than metallic devices, however. The inventor has made many contributions to the field of plasma antennas.
See, for example U.S. Pat. No. 7,453,403 for Tunable Plasma Frequency Devices that discloses a reduced noise and selectively configurable plasma device that is capable of interpreting electromagnetic signals and that has a plasma mechanism with a plasma that is ionizable to a plasma frequency. An ionizing mechanism for ionizing the plasma and a control that is operative to control the ionizing mechanism, ionizes the plasma to the plasma frequency by application of plasma ionizing energy pulses. An interpreting mechanism operates to interpret the electromagnetic signals only in a period between ionization of the plasma with the energy pulses. U.S. Pat. No. 7,453,403 is incorporated here by reference for its teaching of how to establish a plasma in a container of a density and frequency for use as part of a plasma antenna.
U.S. Pat. No. 7,342,549 for Configurable Arrays for Steerable Antennas and Wireless Network Incorporating the Steerable Antennas discloses a reconfigurable array of variable conductive elements provided for reflecting, filtering and steering electromagnetic radiation across a wide range of frequencies. The reconfigurable array is combined with a transmitting antenna to make a steerable antenna. The reconfigurable array surrounds the transmitting antenna and reflects all transmissions except on selected radials where apertures in the reconfigurable array are formed for permitting transmission lobes.
Also see U.S. Pat. No. 6,876,330 for Reconfigurable Antennas that discloses an antenna element comprising at least two conductive elements, and a gas or vapor filled bulb or tube positioned between the conductive elements is provided. The fluid is capable of ionization such that when the fluid in the bulb or tube is energized, the conductive elements electrically communicate with one another, and when the fluid is not energized, the conductive elements do not electrically communicate with one another.
U.S. Pat. No. 5,963,169 for a Multiple Tube Plasma Antenna discloses an antenna in which electromagnetic signals in the high frequency and super high frequency bands are propagated utilizing ionized gas, or plasma. Energized electrodes ionize the gas and the plasma is confined within non-metallic coaxial tubes contained within a non-metallic pressure vessel. Electric field gradients are used to change the shape and density of the plasma to affect the gain and directivity of the antenna. The inner plasma tube acts as the radiating source, while the outer plasma tube is used to change the radiation of the inner tube and to reflect the radiated signal. Instrumentation measures the density of the plasma providing a means to measure incoming signals as well as to regulate the radiation frequency. U.S. Pat. No. 5,963,169 is also incorporated here by reference for its teaching of how to establish a plasma in a container of a density and frequency for use as part of a plasma antenna.
Other relevant patents are U.S. Pat. No. 6,657,594 for a Plasma Antenna System and Method; U.S. Pat. No. 6,700,544 for a Near Field Plasma Reader; U.S. Pat. No. 6,710,746 for an Antenna Having Reconfigurable Length; U.S. Pat. No. 6,812,895 for a Reconfigurable Electromagnetic Plasma Waveguide; U.S. Pat. No. 6,842,146 for a Plasma Filter Antenna System; U.S. Pat. No. 6,870,517 for Configurable Arrays for Steerable Antennas; and U.S. Pat. No. 6,922,173 for a Reconfigurable Scanner and RFID System.
A need remains of a plasma array that can be operated in a wide variety of modes so as to effectively and efficiently transmit, receive, filter, reflect and/or refract radiation.